Yes, Dan is correct, there's a KM action called Filter which has an option called "Process Tokens" which lets you evaluate the contents of a token whose name is stored in a variable.
Over the last week I've posted two or three macros in the Macros part of this website using that action. If you need to examine one of my examples, I'll post a link to one in this message in a few minutes.
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Okay, here's one of my macros which uses that action if you want to see it in action:...